This is a randomized phase lll trial. All patients will receive memantine hydrochoride ( Namenda ) which is a drug shown to improve memory and cognition when given to patients together with whole-brain radiotherapy. Then patients will be randomized to receive regular WBRT or WBRT that does not radiate the hippocampal region of the brain. The hippocampal region of the brain plays an important role in memory and understanding and shielding it from radiation may improve memory and cognition after WBRT. However, it is not known whether not radiating the hippocampal region might increase the risk for recurrences in the brain. Patients must not have had prior WBRT and brain metastases must be 5mm or more from the hippocampus. Patients with leptomeningeal disease do not qualify.

This two-arm randomized trial is being conducted in Germany. It compares the cognitive function (understanding, learning, and memory) of WBRT versus WBRT that avoids radiation to the hippocampal region of the brain, where memory and cognition are stored. The intent is to study and compare both arms in terms of cognition, recurrence in the brain, and overall survival. It is not known if avoiding the hippocampal region of the brain may increase the chance of recurrence in that area.

This phase II single arm study is being conducted in Taiwan. All patients will receive WBRT that avoids the hippocampal region of the brain, where memory and cognition are stored, to see if shielding it from radiation improves cognition and memory. No brain metastases can be larger than 4 cm and patients can't have leptomeningeal disease.

This phase ll randomized trial is taking place in Taiwan. Patients in the trial will receive either conformational WBRT that avoids the hippocampal region of the brain, where memory and cognition are stored, or conformational WBRT that includes the hippocampus. All brain metastases must be at least 5cm from the hippocampus. Patients with leptomeningeal disease are excluded.

This is a phase ll trial looking at a different type of whole brain radiotherapy known as IMRT, which delivers higher doses of radiation to brain metastases while delivering a lower dose of radiation to the rest of the brain. The hope is that the part of the brain without clinical brain metastases will not need as high a dose as the areas that have brain metastases, and that delivering less radiation will reduce toxicity and cognitive side effects.

The purpose of this study is to find out if 18-Fluourocholine can distinguish radiation-caused scarring (called radiation necrosis) occurring in the brain from a recurrence of brain metastases. A pet scan will be done twice the agent (18F-FCHO). This study wil enroll patients who have lesions that are growing afterer stereotactic radiotherapy who will be undgoing brain surgery to determine whether the lesion is radiation necrosis or a recuurrence of metastatic disease in the brain.

The purpose of this clinical trial is to determine whether the use of Trental (pentoxifylline), a drug that improves circulation, and vitamin E can help reduce the incidence of radiation necrosis after radiosurgery. These two drugs are commonly used to treat radiation necrosis when it occurs but this study will try to see if giving these two drugs before radiosurgery can prevent it from every occurring.

This is a single center study of 15 patients with brain lesions being treated at University of North Carolina Hospital. Patients will undergo one FLT-PET-MRI scan before their scheduled surgical biopsy.